GNCC Exhaust DB readings

For those that were there and raced. What type of pipe do you have and what did it register at??

I have a FMF powerbong header and Bills thunder silencer with 5 inches cut off. I registered at 97 db.

[ChuckSpears]

They didn't give me an exact db level, but they said it was over 110. I have a TC pipe, I'm sorry...had a TC Pipe. Looks like I'm changing before the next race.

[wyndzer]

Somebody tell me what a Dale w/ HMF was?

[coorsinmyc-bak]

i had an hmf slip on/on a yfz 450 and got a 102 db.my buddy has a full hmf header and pipe and got a 104 reading.

[Dunlap]

We had 3 YFZs with brand new White Bros. full systems and we had a 101,103 and a 105 db.

[Dave400ex]

Chuck I was afraid the TC would be way to loud for racing. I think I am going to switch to an HMF.

[joedirt]

Were the tech guys doing it right or were they jamming the meter up the pipe and saying your too loud like they done before

[cheetah]

They didn't tell me mine either. I had an HMF on the dale and all I can say is it didn't pass.:( All they told me was HMF sucks. I take it not too many HMFs passed judging from the angry faces coming out.

[cheetah]

Originally posted by joedirt
Were the tech guys doing it right or were they jamming the meter up the pipe and saying your too loud like they done before

No they had a tape on it and measured out 1 foot I believe.

[mtdewracing]

HEY GUYS DID ANYONE GET DQ'ED BECAUSE THEY WERE TO LOUD? THANKS IN ADVANCE -RICK

[LS@GtThunder]

400EX - 2 Inch collector, 7.25 inch canistor, 6.5 inch core, = 104 db,

add a Promotobillit quiet core (installed on an angle = 91 db.

LS

[member]

ok.. i went to the race and i was looking at an hmf pipe and i looked inside of it and noticied all it is, is a pipe with packing.. there is nothing in the center... so my question is why do you spend 200 bucks on that when you could just go to a muffler shop and get on made for 14 bucks???.. well at least here they can make one for 14 bucks

[Silverfox@C&DRacing]

400ex with sparks x6 (I could not get it at the correct RPM my thumb throttle it touchy) said I was around 101-104
Colby had the Cannondale and hmf pipe I think he was around 97 or 99.

[cheetah]

So did anyone else with a dale and HMF pass? Like I said he never told me mine just said "damn HMF sucks":rolleyes: I'm not sure if they were consistent in every bike's RPM range to check it though. I may try it again next round and hope I pass this time. I don't see where Colby can get 6+db quieter than mine without it being a difference in how they tested them. Oh Dusty did you go to tech on Friday or Saturday because I noticed it looked like more passed on Saturday than Friday.:confused:

[79400ex]

I had 400ex with a 440 kit and Big Gun Race exhaust on it. The db reading was 102. However, I don't beleive I had 3500rpm on it.

As for the question about did he fo it wright,? He held it one foot back and about a 45degree angle.

[Scott Kawi700]

Originally posted by Mickey Dunlap
We had 3 YFZs with brand new White Bros. full systems and we had a 101,103 and a 105 db.

Looks to me like there may be a flaw in the testing!!!

Personaly my kfx 700 w/ dual HMF and no quite cores passed, they did not give me the reading they just said it passed. Another 700 with the same exact set up failed but when check again later passed and nothing was modified.

I have a problem with a few things in this testing.

1 There was no measureing of any kind on where the meter was held for my test

2 They asked ME to give the bike ABOUT 1/4 throttle for the test.

3 This test is done out in the open with no reguard for backround noise levels.

I think they need to come up with a better plan before they think about DQing anyone for loud pipes! IMO!

[Wingnut]

They said the meter wouldn't even give a reading for mine.:confused: It was stock though.

[Meek]

I got a 102 on a stock motor, white brothers e, that was repacked 2 months ago

[Taco]

95db with a old Pro Circuit T4 and stock motor

[komatsu kid]

pro-circurt t-4 105db

[ranger400ex]

They did not even follow their own sound testing rules....
1)bike must be in an open area w/no sound relfecting/trapping devices(ie the eazyup)
2)no source of background noise within 16ft, in grass, but no more than 6" inches tall, no testing on bare or loose soil, test at 45deg angle from centerline of exhaust @ 20" from pipe outlet. testing should not be done if ambient noise is within 15db of the sound being measured(all the meters were reading 89+ just holding them up in the air)
3)run bike @ optimum RPM per manufacturer specs, or AMA guidelines(this varies for every manufacturer)
Mister RPM gauge guy, didn't ever get a reading on a YFZ till I pointed out he was on the wrong side of the bike for the CDI box!!!!!

It was really bad, and if everyone is willing to stand up, the testing either needs to be done right, or the idea thrown out. I think the best would be to do the testing right, hit only some riders(misc check) DONT skip the pros, then write up an amateur(they did this a ton!!!!)
Racer Productions/ATVA either do it right, per your exact rules, or leave it alone.


I videotaped the entire tech sessions, 2.5hrs worth of tape...only a couple guys actually got a somewhat fair test, the others were a complete joke...both of the guys testing asked me to quit taping, I told them it was for proof of how the testing was conducted. Every pipe manufaturer, every type of quad, some failed, some just barely, and some under. Several that were dead exact setup, one failed, one close, and the next under...so obviously something is wrong.

I ran db testing for Autografix @ our competetions, along with our engineering group here at work....everything done this weekend was wrong, and they need to take the "LIST" and toss it out...try doing it right this next time, then think about warnings.

[Wingnut]

Did anyone ever see a dirtbike get checked this weekend? When I left, nobody was checking their sound.

[TRX500]

I may be wrong, but I think even testing for sound is stupid. Every local stock car dirt track in my area can be heard (when racing) for miles away. Is a race suppose to be loud? Or is it because some tree hugging sob has a problem with quads? I don't believe any Quad race makes 1/2 the noise of a stock car race that runs every saturday night here in the summer. I would think that there are several small communities that would like to have 2000+ people spending money in there local businesses on a weekend just for a little noise. This is nothing but bullship!

[cdalejef]

My Dale with a full HMF blew a 100. All of our Dales with HMF's passed easily.

They were only giving out warnings to people that didn't pass.

yfz 450 with full HMF exhaust. well under 100db with quit core!

[cdalejef]

I didn't have quiet core in mine

[pairanutz]

my 400ex full big gun 100db

xcchucks 400ex with white brother r4 slip on 101 db

[bradley300]

my 350ex was and i quote "right around about 100 or so" with a wb header and pc t-4 silencer, no quiet core

[gncc571]

Originally posted by Wingnut
Did anyone ever see a dirtbike get checked this weekend? When I left, nobody was checking their sound.

They were checking the bikes when we were leaving.

[Shawn H]

Stroked out Z450 Complete HMF and blew 104db's

[cheetah]

Originally posted by Jeff@QuadShop
My Dale with a full HMF blew a 100. All of our Dales with HMF's passed easily.

They were only giving out warnings to people that didn't pass.

I may try it again at Florida and see what happens. There were very few dales on there and I would say with all of yours and others on this site we can account for probably 3/4 if not more of dales with HMFs. The way it sounds mine is the only one that didn't pass and I was supposedly way too loud and I can't see that being true when we have the exact same setup. Like I said a lot more people passed on Saturday than Friday and it didn't look like any of them knew what they were doing, but the Saturday guys seemed a little better.

[Cron]

I was just wondering, I know GNCCer did. but how many other HMF users had the queit core in when tested? I just ordered my HMF Quiet Core and was hoping it would quiet it down some.

Maybe I should buy some new exhuast packing and re pack my pipe. I dont think it ever has been. How do I know when it needs to be re packed?

[mmills023]

As a side note, i got a 99 in Florida, and a 105 in Georiga.....nothing changed!!!.......


Mike

[markk]

Full system white bros. E-series on 416 i blew a 103 at TX. with no spark arrestor! would i be able to tell a diffrence if i bought a HMF for my quad over my white bros?